Method and system for content categorization

ABSTRACT

Embodiments of the present invention disclose a method for content categorization, where the method comprises transmitting, by a content categorization request entity, a categorization ability negotiation request to a content categorization providing entity to request the categorization ability of the content categorization providing entity; receiving the categorization capability of the content categorization providing entity returned by the content categorization providing entity. Furthermore, embodiments of the present invention disclose a system for content categorization, content categorization request entity and content categorization providing entity. Categorization ability negotiation or subscription helps to learn the content categorization ability so that the content categorization request entity or content categorization providing entity may mutually and accurately acquire content categorization capability information without delay.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/830,152, filed Jul. 2, 2010, which is a continuation of InternationalApplication No. PCT/CN2008/072526, filed on Sep. 25, 2008. TheInternational Application claims priority to Chinese Patent ApplicationNo. 200810065626.5, filed on Jan. 23, 2008. The afore-mentioned patentapplications are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

Embodiments of the present invention mainly relate to the communicationstechnology, and more particularly to a method, a system, a contentcategorization request entity, and a content categorization providingentity for content categorization.

BACKGROUND OF THE INVENTION

With the rapid development of network technology and various informationtechnologies, the range of content accessible to users graduallyeliminates temporal and spatial limits, and greatly increases theprobability that users will be exposed to such content as pornography,violence and viruses that are unhealthy and menacing to the clientterminals, so that there is an ever-increasing demand for the screeningof communication content. Currently available screening technologiesinclude list screening technology, keyword screening technology,template screening technology, categorization screening technology, andso on.

Referring to FIG. 1, which is a structural schematic view illustrating aconventional Categorization Based Content Screening (CBCS) system, thesystem mainly comprises two parts: a content categorization providingentity 201 and a content screening unit 202. In practical application,the CBCS system 200 may simultaneously include these two units, and itis also possible for the two units to constitute a server. That is, thecategorization providing entity 201 and the content screening unit 202can operate in the same and single server. It is further possible forthe two units to separately operate each in a different server, in whichcase networking and deployment are carried out upon actual demand. Thecontent screening unit 202 in the CBCS system 200 and the contentcategorization request entity 100 (such as a content provider) externalto the CBCS system 200 can both obtain categorical information of acertain content from the content categorization providing entity 201 viaa CBCS-1 interface, and the content categorization providing entity 201further provides a CBCS-3 interface capable of associating contentinformation with category upon request. The internal and the externalentities that request operations from the content categorizationproviding entity via the CBCS-1 interface and the CBCS-3 interfaceuniformly are called as the content categorization request entity 100,where the request operations include requesting content categorizationand requesting association of content with category.

At present, with the development of the content categorizationinterfaces such as the CBCS-1 interface, the interfaces have beengradually multiplied in types from the initial simple modes (such asoutput of category obtained via content or content-introduced input) toinvolve multiplicity of parameters (such as the content categorizationrule, content identification, digital abstract algorithm, and digitalsignature algorithm, etc.). These parameters are present with pluralchoices and possibilities; for example, the content categorization ruleincludes the Entertainment Software Rating Board (ESRB), and the MotionPicture Association of America (MPAA), etc. On the other hand, besidesthe parameters involved in the CBCS-1 request message, the responsemessage also involves some parameters. Similarly, the contentcategorization providing entity associates the content information withthe category, and it likewise deals with the similar problems of aplurality of selections and determinations of the parameters supportedby the content categorization providing entity. With the enrichment ofsuch categorization processing, parameters are simultaneously generatedthat are supported by different content categorization entities(including the content categorization request entity and the contentcategorization providing entity). In other words, the categorizationabilities might be different.

In view of the conventional systems discussed above, the inventors foundduring implementation of the present invention that the categorizingability of the content categorization providing entity relates to manyaspects and corresponds to multiplicity of parameters, but there lacksan explicit and efficient mechanism for categorization abilitynegotiation between the content categorization request entity and thecontent categorization providing entity. The result is often that thecontent categorization providing entity cannot categorize the contentfor the provided content information or associate the content with thecategory, or that the content categorization result provided by thecontent categorization providing entity is rendered invalid, thusseverely affecting the validity of content categorization orassociation.

SUMMARY OF THE INVENTION

In view of the above, technical solutions provided in the embodimentsdescribed below solve a problem of lack of a mechanism forcategorization ability negotiation between the content categorizationrequest entity and the content categorization providing entity inconventional systems, where the problem leads to failure due to absenceof support for the categorization ability when the contentcategorization request entity requests the content categorizationproviding entity for operations related to content categorization, orwhen the content categorization providing entity transmits the contentcategorization request entity the operation results related to thecontent categorization.

Embodiments of the present invention provide a method for contentcategorization. The method comprises the following steps:

a content categorization request entity transmitting a categorizationability negotiation request to a content categorization providingentity, for requesting categorization ability of the contentcategorization providing entity; and

receiving the categorization ability of the content categorizationproviding entity returned by the content categorization providingentity.

Embodiments of the present invention further provide a method forcontent categorization. The method comprises the following steps:

receiving a categorization ability negotiation request transmitted froma content categorization request entity; and

returning categorization ability of a content categorization providingentity to the content categorization request entity.

Embodiments of the present invention further provide a method forcontent categorization. The method comprises the following steps:

subscribing to categorization ability of a content categorizationproviding entity from the content categorization providing entity; and

receiving the categorization ability transmitted from the contentcategorization providing entity.

Embodiments of the present invention yet provide a method for contentcategorization. The method comprises the following steps:

receiving a subscription request for categorization ability of a contentcategorization providing entity transmitted from a contentcategorization request entity; and

transmitting the categorization ability of the content categorizationproviding entity to the content categorization request entity.

Embodiments of the present invention further provide a system forcontent categorization. The system comprises:

a content categorization request entity, adapted to transmit acategorization ability negotiation request to a content categorizationproviding entity to request categorization ability of the contentcategorization providing entity, and receive the categorization abilityof the content categorization providing entity returned by the contentcategorization providing entity; and

a content categorization providing entity, adapted to receive acategorization ability negotiation request transmitted from a contentcategorization request entity, and return the categorization ability ofthe content categorization providing entity to the contentcategorization request entity.

Embodiments of the present invention further provide a contentcategorization request entity. The content categorization request entitycomprises:

a categorization ability requesting unit, adapted to requestcategorization ability from a content categorization providing entity;and

a categorization ability receiving unit, adapted to receive thecategorization ability of the content categorization providing entity.

Embodiments of the present invention further provide a contentcategorization providing entity. The content categorization providingentity comprises:

a categorization ability interacting unit, adapted to receive acategorization ability request transmitted from a content categorizationrequest entity; and

a categorization ability providing unit, adapted to returncategorization ability of the content categorization providing entity tothe content categorization request entity.

As can be seen from the foregoing technical solutions, embodiments ofthe present invention learn of the categorization ability of the contentcategorization providing entity via the categorization abilitynegotiation or the subscription request, and it is further possible forthe content categorization providing entity to learn of thecategorization ability supported by the content categorization requestentity via the categorization ability negotiation or subscription.Therefore, it is made possible for the content categorization requestentity or the content categorization providing entity to obtain themutual content categorization ability information in a detailed, clear,exact and timely manner, and thus the rate of success of requests andoperations related to content categorization is increased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural schematic view illustrating a conventionalCategorization Based Content Screening (CBCS) system;

FIG. 2 is a structural schematic view illustrating a system for contentcategorization provided by the embodiments of the present invention;

FIG. 3 is a flowchart illustrating a method for content categorizationprovided by Embodiment 1 of the present invention;

FIG. 4 is a flowchart illustrating a method for content categorizationprovided by Embodiment 2 of the present invention;

FIG. 5 is a flowchart illustrating a method for content categorizationprovided by Embodiment 5 of the present invention;

FIG. 6 is a flowchart illustrating another method for contentcategorization provided by Embodiment 5 of the present invention; and

FIG. 7 is a flowchart illustrating still another method for contentcategorization provided by Embodiment 5 of the present invention.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

Embodiments of the present invention provide a method for contentcategorization. The method includes: a content categorization requestentity transmitting a categorization ability negotiation request to acontent categorization providing entity to request categorizationability of the content categorization providing entity; or subscribingto categorization ability of a content categorization providing entityfrom the content categorization providing entity; receiving thecategorization ability of the content categorization providing entitytransmitted from the content categorization providing entity; furtherrequesting content categorization or requesting association of contentwith category according to the obtained categorization ability of thecontent categorization providing entity, and further providingcategorization ability supported by the content categorization requestentity to the content categorization providing entity, wherein thecontent categorization providing entity can provide the supportedcontent categorization result to the content categorization requestentity according to the categorization ability supported by the contentcategorization request entity.

Referring to FIG. 2, which is a structural schematic view illustrating asystem for content categorization provided by the embodiments of thepresent invention, the system specifically includes: a contentcategorization request entity 300 and a content categorization providingentity 400. The content categorization request entity 300 canspecifically be a content providing system controlled by an operator ora service provider; the content screening unit 202 in the CBCS system200 in FIG. 1; or a content information and category associating systemcontrolled by an operator or a service provider. The contentcategorization providing entity 400 can specifically be a contentcategorization server, or the CBCS system 200 consisting of a contentcategorization server and a content screening server.

The content categorization request entity 300 includes a categorizationability requesting unit 301 and a categorization ability receiving unit302.

The categorization ability requesting unit 301 requests categorizationability from the content categorization providing entity.

The categorization ability receiving unit 302 receives thecategorization ability of the content categorization providing entity.

The categorization ability requesting unit 301 can specifically be anegotiating unit that transmits a categorization ability negotiationrequest to the content categorization providing entity 400 to requestthe categorization ability of the content categorization providingentity. The categorization ability receiving unit 302 receives thecategorization ability of the content categorization providing entityreturned by the content categorization providing entity 400.

The negotiating unit can further carry the categorization abilitysupported by the content categorization request entity 300 in thecategorization ability negotiation request to be provided to the contentcategorization providing entity 400, or receive the categorizationability negotiation request transmitted by the content categorizationproviding entity 400, and return the categorization ability supported bythe content categorization request entity 300 to the contentcategorization providing entity 400.

Specifically, it is possible to send a categorization abilitynegotiation request to the content categorization providing entity 400.The request can include information of the categorization abilitysupported thereby and related to content categorization or content andcategory association, for instance, information indicating that thecategorization requester can provide the content in the format of apacket compressed by ZIP or RAR, etc., or information indicating theacceptable content categorization rule result, etc. The categorizationability receiving unit 302 receives the categorization ability returnedby the content categorization providing entity 400, and can specificallyreceive the response to the categorization ability negotiation requesttransmitted thereto by the content categorization providing entity 400according to the categorization ability negotiation request. Theresponse to the request includes the categorization ability informationsupported by the content categorization providing entity 400 and relatedto the content categorization. The categorization ability of the contentcategorization providing entity includes, but not limited to, one of thefollowings or a combination thereof: a content type supported by thecontent categorization providing entity; a content coding formatsupported by the content categorization providing entity; a contentlanguage supported by the content categorization providing entity; acontent size supported by the content categorization providing entity; acontent locator supported by the content categorization providingentity; a content identifier supported by the content categorizationproviding entity; a content abstract type supported by the contentcategorization providing entity; a digital signature algorithm supportedby the content categorization providing entity; and a contentcategorization rule supported by the content categorization providingentity.

The categorization ability requesting unit can specifically be asubscribing unit that subscribes to the categorization ability of thecontent categorization providing entity from the content categorizationproviding entity 400. The categorization ability receiving unit 302receives the categorization ability transmitted from the contentcategorization providing entity 400. Specifically, it is possible tosubscribe the categorization ability of the content categorizationproviding entity and the changing items of the categorization abilitythereof from the content categorization providing entity 400, and toreceive the categorization ability transmitted from the contentcategorization providing entity 400 as well as the changedcategorization ability.

During the process of practical application, the content categorizationrequest entity can further include, but not limited to, at least one ofthe following units:

a transmitting unit 303 that requests content categorization or requestsassociation of content with category from the content categorizationproviding entity 400 according to the category ability of the contentcategory providing entity;

a receiving unit 304 that receives categorization result of the contentor association result returned by the content categorization providingentity 400;

a content processing unit 305 that correspondingly processes contentinformation to be categorized according to the categorization abilityreceived from the content categorization providing entity, and requestscontent categorization from the content categorization providing entity400 via the transmitting unit with the processed content information;

a configuring unit 306 that configures categorization ability and/orconfidence verification ability supported by the content categorizationrequest entity according to the categorization ability received from thecontent categorization providing entity;

a storing unit 307 that stores the categorization ability of the contentcategorization providing entity obtained from the content categorizationproviding entity; and

a determining unit 308 that determines whether valid categorizationability of the content categorization providing entity has been stored,and notifies, if valid categorization ability of the contentcategorization providing entity has been stored, the content processingunit to process the content information according to the storedcategorization ability of the content categorization providing entity.

The transmitting unit 303 requests content categorization or requestsassociation of content with category from the content categorizationproviding entity with the processed content information.

The content categorization providing entity 400 comprises acategorization ability interacting unit 401 and a categorization abilityproviding unit 402.

The categorization ability interacting unit 401 receives thecategorization ability transmitted from the content categorizationrequest entity 300.

The categorization ability providing unit 402 returns the categorizationability of the content categorization providing entity to the contentcategorization request entity 300.

The categorization ability interacting unit 401 can specifically be anegotiating unit that receives the categorization ability negotiationrequest transmitted from the content categorization request entity 300.Moreover, the negotiation request can include the categorization abilitysupported by the content categorization request entity. Thecategorization ability providing unit 402 returns the categorizationability of the content categorization providing entity to the contentcategorization request entity 300.

The negotiating unit can further transmit the categorization abilitynegotiation request to the content categorization request entity 300,and receive the categorization ability supported by the contentcategorization request entity returned by the content categorizationrequest entity 300.

Specifically, the negotiating unit can obtain the categorization abilitysupported by the content categorization request entity and related tothe content categorization by receiving the categorization abilitynegotiation request supported by the content categorization requestentity, and carry the categorization ability supported thereby byreturning the message in response to the categorization abilitynegotiation request, for instance, such information of thecategorization ability as the different content formats and parameterssupported by the content categorization providing entity, or checkalgorithm of the pre-categorization information provided by the contentcategorization providing entity.

Additionally, the categorization ability interacting unit 401 canspecifically be a subscribing unit that receives a subscription requesttransmitted from the content categorization request entity 300 forsubscribing to the categorization ability of the content categorizationproviding entity. The categorization ability providing unit 402transmits the categorization ability (which can further include changedcategorization ability) of the content categorization provider to thecontent categorization request entity according to the subscriptionrequest. The subscribing unit can further subscribe the categorizationability supported by the content categorization request entity from thecontent categorization request entity 300, and receive thecategorization ability transmitted from the content categorizationrequest entity as well as the changed categorization ability.

During the process of practical application, the content categorizationproviding entity can further include, but not limited to, one of thefollowing units:

a receiving unit 403 that receives a request for content categorizationor a request for association of content with category transmitted by thecontent categorization request entity 300 according to thecategorization ability of the content categorization providing entity,and specifically receives a request message for content categorizationor an association message transmitted by the content categorizationrequest entity according to the categorization ability of the contentcategorization providing entity, which message includes information ofthe content to be categorized or relevant information necessary forassociation;

a categorizing unit 404 that categorizes the content according to therequest for content categorization or performs categorization accordingto the categorization ability supported by the content categorizationrequest entity;

an associating unit 405 that associates the content with the categoryaccording to the request for content and category association;

specifically, the categorizing unit 404 and the associating unit 405 areused to categorize or associate the content information according to therequest for content categorization or the request for association ofcontent with category of the content categorization request entity 300;if no category information is carried in the request for association, itis necessary to firstly perform categorization and then association;alternatively, content categorization is performed according to thecategorization ability supported by the content categorization requestentity and related to the content categorization, and the contentcategorization result is provided to the content categorization requestentity 300 via the transmitting unit 406;

a transmitting unit 406 that transmits result of categorizing thecontent or result of associating the content with the category to thecontent categorization request entity 300; and

a storing unit 407 that stores the categorization ability supported bythe content categorization request entity returned by the contentcategorization request entity 300, and updates the stored categorizationability of the content categorization providing entity according tochange information of the categorization ability returned by the contentcategorization request entity.

As should be noted, the categorization ability negotiation can berealized by different modes, for instance, it can be realized bytransmitting content categorization ability request message andcorresponding response message, such as by transmitting contentcategorization ability negotiation message and corresponding responsemessage; it can also be realized by attaching categorization abilitydescriptive information in authentication interaction process, or incontent categorization request message and corresponding responsemessage, or in association of content with category request message orassociation request response message. The specific realization isdescribed in greater detail in the following embodiments of the methodprocess. The embodiments of the present invention are not restricted tothese modes of implementation, as other methods for realizingcategorization ability negotiation also fall within the protection scopeof the embodiments of the present invention.

Example is taken below with the aforementioned system applied in acontent categorization process based on categorization abilitynegotiation to describe the specific process of the embodiments of thepresent invention in greater detail. As shown in FIG. 3, which is aflowchart illustrating a method for content categorization provided byEmbodiment 1 of the present invention, the following steps arespecifically included:

Step 301: The content categorization request entity transmits a contentcategorization ability request, such as a content categorization abilitynegotiation request message, to the content categorization providingentity.

Because the categorization ability supported by the contentcategorization providing entity is not known, such as the supportedcontent format, language, content identifier type, content locator typeand packing format, the content categorization request entity needs toobtain the categorization ability of the content categorizationproviding entity. This is to provide corresponding content informationto the content categorization providing entity for performing contentcategorization.

Step 302: The content categorization providing entity returns thecorresponding content categorization ability information according tothe categorization ability supported thereby. The information includes,but not limited to, different content formats, coding methods, languagessupported by the content categorization providing entity, or informationof categorization ability such as the digital signature algorithmprovided by the content categorization providing entity for thepre-categorized content to perform confidence verification, wherein whenthe content categorization request entity is a content screening entity,the content screening entity configures the confidence verificationability of itself, such as the confidence verification algorithm,according to the confidence verification algorithm obtained from thecontent categorization providing entity. This can ensure check on thepre-categorized content.

Step 303: The content categorization request entity transmits a contentcategorization request carrying therewith the content information to becategorized or address information of the content according to thecategorization ability supported by the content categorization providingentity, and the content categorization providing entity obtains thecorresponding content information according to the address information.

Step 304: The content categorization providing entity transmits thecontent categorization ability request, such as a content categorizationability negotiation request message, to the content categorizationrequest entity.

Because the content categorization providing entity does not know thecategorization ability supported by the content categorization requestentity, the content categorization providing entity needs to obtain thecategorization ability, such as the categorization rule, supported bythe content categorization request entity prior to performing contentcategorization. This is to transmit the content categorization abilityrequest message to the content categorization request entity.

Step 305: The content categorization request entity returns thecategorization ability supported thereby, like such information as thesupported categorization rule, etc.

Step 306: The content categorization providing entity performs contentcategorization according to the content information provided by thecontent categorization request entity and in accordance with thecategorization ability supported by the content categorization requestentity, such as the supported standard categorization result.

Step 307: The content categorization providing entity feeds back thecorresponding content categorization result to the contentcategorization request entity.

As should be noted, the specific sequence of the aforementionedcategorization ability negotiating steps 304-305 and the negotiatingsteps 301-302 can be flexibly set, for instance, by setting steps304-305 immediately after steps 301-302, in other words, the contentcategorization request entity transmits the content categorizationrequest after completing categorization ability negotiation between thetwo.

Moreover, the process of association of content with category isconsistent in principle with the aforementioned process of contentcategorization, and the different steps between the two rest in thefollowing: If there is categorization that corresponds to the contentrequired to be categorized, steps 306-307 are changed to performingassociation of content with category by the content categorizationproviding entity, and the specific association process can be toestablish a correspondence between the content and the correspondingcategorization, to maintain and store the correspondence, and can alsobe to perform association in other modes to return the result ofassociation to the content categorization request entity. If there is nocategorization performed corresponding to the content information, step306 is retained, that is to say, the content is first categorized, andthe step of association of content with category is then added; in otherwords, content and category are associated according to thecategorization result of step 306, and the association result isreturned to the content categorization request entity.

As shown in FIG. 4, which is a flowchart illustrating a method forcontent categorization provided by Embodiment 2 of the presentinvention, the following steps are specifically included:

Step 401: The content categorization request entity transmits a contentcategorization ability request, such as a content categorization abilitynegotiation request message, to the content categorization providingentity.

The content categorization ability negotiation request message includesthe categorization ability supported by the content categorizationrequest entity per se, and the categorization ability supported by thecontent categorization providing entity requested from the contentcategorization providing entity.

Step 402: The content categorization providing entity returns itscategorization ability.

Step 403: The content categorization request entity transmits a contentcategorization request, which carries therewith the content informationto be categorized or also carries the address information of the contentfor the content categorization providing entity to obtain thecorresponding content information in accordance with the addressinformation, according to the categorization ability of the contentcategorization providing entity.

Step 404: The content categorization providing entity performscategorization according to the content information provided by thecontent categorization request entity and in accordance with thecategorization ability supported by the content categorization requestentity.

Step 405: The content categorization providing entity feeds back thecorresponding content categorization result to the contentcategorization request entity.

As should be noted, the categorization ability negotiation between thecontent categorization request entity and the content categorizationproviding entity can also be realized by the following mode, namely,attaching an additional content categorization ability descriptiveexplanation in the interacting process of any content categorization.For instance, at the same time when the content categorization requestentity transmits the content information to the content categorizationproviding entity to request for categorization, the categorizationability information is carried therewith; the content categorizationproviding entity carries its categorization ability information whilereturning the categorization result, and it is also possible to carrythe corresponding categorization ability information, etc. in theauthentication message and the authentication response message.

The specific process of the content categorization ability descriptiveinformation attached in the content categorization request and responsemessage (the specific form of the message is not limited, and it ispossible to include the authentication interaction message, theassociation of content with category request and the response message,etc.) is as shown in the following Embodiment 3, and includes thefollowing steps:

Step S11: The content categorization request entity transmits thecontent categorization request (which may include the contentinformation or the address information of the content) to the contentcategorization providing entity, and the request includes thecategorization ability information supported by the contentcategorization request entity.

Step S12: If the content categorization providing entity cannot identifythe content information, the content categorization providing entityreturns error information, attaches the categorization abilityinformation supported by the content categorization providing entity,and the process goes to step S13; if the content categorizationproviding entity can identify the content information, the process goesto step S14.

Step S13: The content categorization request entity reorganizes thecontent according to the categorization ability supported thereby asreturned by the content categorization providing entity and transmitsthe content information again to the content categorization providingentity to request for categorization.

Step S14: The content categorization providing entity performs contentcategorization according to the categorization ability supported by thecontent categorization request entity.

Step S15: The content categorization providing entity returns thecontent categorization result of step S14 to the content categorizationrequest entity.

Moreover, if the process is performed according to S11-S12-S14, i.e. thecontent categorization providing entity can identify the contentinformation transmitted from the content categorization request entity,the content categorization result returned by the content categorizationproviding entity in step S15 can carry the categorization abilityinformation supported thereby, and, after receiving the categorizationability information supported thereby as provided by the contentcategorization providing entity, the content categorization requestentity can further store the categorization ability informationsupported by the content categorization providing entity, and canspecifically store the information in the mode of establishing a mappingrelationship table, for example, to establish a mapping relationshiptable for the content categorization providing entity and thecategorization ability supported by the content categorization providingentity. This is to provide the content information of the categorizationability supported by the content categorization providing entity inaccordance with the mapping table at the next time when categorizationis requested from the content categorization providing entity. It isthus possible to cancel the categorization ability supported by thecontent categorization providing entity as negotiably provided from thesubsequent content categorization request interaction, and merely tonegotiably provide the categorization ability supported by the contentcategorization request entity, thereby simplifying the interactiveprocess of content categorization, and enhance the efficiency of contentcategorization. Furthermore, the content categorization request entitycan further subscribe the content categorization ability changinginformation from the content categorization providing entity—see thedetailed description in Embodiment 5 for the specific process thereof.

Of course, in other modes of execution described in the embodiments ofthe present invention, after obtaining the categorization abilityinformation supported by the content categorization providing entity,the content categorization request entity can in all cases store thecategorization ability supported by the content categorization providingentity by establishing a mapping relationship table, and can furthersubscribe the categorization ability changing information. Similarly,the content categorization providing entity can also store thecategorization ability supported by the content categorization requestentity after obtaining the categorization ability supported by thecontent categorization request entity, and can also store the ability byestablishing a mapping relationship table; it is thus possible to cancelthe categorization ability supported by the content categorizationrequest entity as negotiably provided from the content categorizationrequest interaction, and merely to negotiably provide the categorizationability supported by the content categorization providing entity,thereby simplifying the interactive process of content categorization,and enhance the efficiency of content categorization. If both of theentities store the corresponding categorization abilities, it sufficesto query in advance the categorization ability supported by the otherparty in the content categorization request, and then to adjust thecorresponding content information format according to the categorizationability, or to adjust the categorization rule, so as to quickly, highlyefficiently and successfully complete such operations related to thecategorization ability as the content categorization request or theassociation request (when the aforementioned process is directed to theassociation of content with category).

As understandable, after the content categorization request entitystores the categorization ability obtained from the contentcategorization providing entity or the content categorization providingentity stores the categorization ability supported by the contentcategorization request entity, each of the embodiments of the presentinvention can further includes the following steps:

It is determined whether valid categorization ability of the contentcategorization providing entity or the categorization ability supportedby the content categorization request entity has been stored. The validcategorization ability can be determined by the methods such asdetermining whether storage of the information has exceeded the presetvalidity period, whether the stored categorization ability informationis complete, and whether a corresponding control strategy is conformedwith when there is strategy control, and so on. If the validcategorization ability of the content categorization providing entityhas been stored, association of content with category is requested fromthe content categorization providing entity according to the storedcategorization ability of the content categorization providing entity,or categorization is performed according to the categorization abilitysupported by the content categorization request entity, and thecorresponding categorization result is returned. If the validcategorization ability of the content categorization providing entityhas not been stored, a categorization ability negotiation request or asubscription request is transmitted to the content categorizationproviding entity, and association of content with category is requestedfrom the content categorization providing entity according to thecategorization ability received from the content categorizationproviding entity.

As should be explained, the similar method can be employed for thereverse content categorization ability negotiation, with the followingspecific steps as how to negotiate:

In step S21, the content categorization request entity transmits thecontent categorization request (including the content information) tothe content categorization providing entity, and the request does notinclude the categorization ability information supported by the contentcategorization request entity.

In step S21, the content categorization request entity transmits thecontent categorization request (including the content information) tothe content categorization providing entity, and the request does notinclude the categorization ability information supported by the contentcategorization request entity.

Steps S22-S23 are the same as steps S12-S13.

Step S24: The content categorization providing entity performs contentcategorization according to the content information provided by thecontent categorization request entity.

Step S25: The content categorization providing entity returns thecontent categorization result of step S24 to the content categorizationrequest entity.

Step S26: The content categorization request entity receives the contentcategorization result returned by the content categorization providingentity, the categorization is successful and the process is ended if theresult is supported thereby; however, if the categorization result isnot supported thereby, the content categorization request entity returnsan error message to the content categorization providing entity, andsimultaneously attaches the categorization ability information supportedby the content categorization request entity.

Step S27: The content categorization providing entity performs thecontent categorization again according to the received categorizationability information supported by the content categorization requestentity.

Step S28: The content categorization providing entity returns thecontent categorization result of step S27 to the content categorizationrequest entity. If the process is performed according to S21-S22-S24,i.e. when the content categorization providing entity can identify thecontent information transmitted from the content categorization requestentity, it is possible to further carry the categorization abilityinformation supported by the content categorization providing entity inthe categorization result message returned from step S25 or S28, so thatthe content categorization request entity stores the categorizationability information.

As should be noted, the interactive process of content categorization isadded to the two aforementioned embodiments in a certain sense, and ifthe initial content formats are not matched, there will be severalrounds of mutual information interactions. However, the process ofcontent categorization ability negotiation is reduced in the scenario ofrelatively simple content format, and this facilitates enhancement ofthe speed and efficiency of content categorization.

Specific process of the content categorization ability descriptiveinformation carried in the content categorization initial requestmessage is described in the following Embodiment 4, and includes thefollowing steps:

Step S31: The content categorization request entity transmits thecontent categorization initial request message, which is not restrictedin type, and which includes the categorization ability informationsupported by the content categorization request entity and the formatinformation of the content information to be categorized fortransmission.

Step S32: The content categorization providing entity returns an initialrequest response message to the content categorization request entity.If the content categorization providing entity supports the format ofthe content information, it returns an initial request success responsemessage; if the content categorization providing entity does not supportthe format of the content information, the content categorizationproviding entity attaches the categorization ability informationsupported by the content categorization providing entity in the returnedinitial request response message.

Step S33: The content categorization request entity transmits a contentcategorization message, which includes the content information, to thecontent categorization providing entity according to the initial requestresponse message of the content categorization providing entity.

Step S34: The content categorization providing entity performs contentcategorization according to the categorization ability supported by thecontent categorization request entity.

Step S35: The content categorization providing entity returns thecontent categorization result of step S34 to the content categorizationrequest entity.

Of course, it is also possible not to include the categorization abilityinformation supported by the content categorization request entity inthe content categorization initial request message transmitted in stepS31, but to include only the information describing the format of thecontent information to be categorization for transmission, with thefollowing specific steps:

Step S41: The content categorization request entity transmits a contentcategorization initial request message that includes the formatinformation of the content information to be categorized fortransmission.

Step S42: The content categorization providing entity returns an initialrequest response message to the content categorization request entity,if the content categorization providing entity supports the format ofthe content information, it returns an initial request success responsemessage; if the content categorization providing entity does not supportthe format of the content information, the content categorizationproviding entity attaches the categorization ability informationsupported by the content categorization providing entity in the returnedinitial request response message.

Step S43: The content categorization request entity transmits a contentcategorization request message, which includes the content information,to the content categorization providing entity according to the initialrequest response message of the content categorization providing entity.

Step S44: The content categorization providing entity performs contentcategorization according to the content information provided by thecontent categorization request entity.

Step S45: The content categorization providing entity returns thecontent categorization result of step S44 to the content categorizationrequest entity.

Step S46: The content categorization request entity receives the contentcategorization result returned by the content categorization providingentity, the categorization is successful and the process is ended if theresult is supported thereby; however, if the categorization result isnot supported thereby, the content categorization request entity returnsan error message to the content categorization providing entity, andsimultaneously attaches the categorization ability information supportedby the content categorization request entity.

Step S47: The content categorization providing entity performs thecontent categorization again according to the received categorizationability information supported by the content categorization requestentity.

Step S48: The content categorization providing entity returns thecontent categorization result of step S47 to the content categorizationrequest entity. If the content categorization providing entity does notreturn the categorization ability supported thereby to the contentcategorization request entity in step S42, the content categorizationproviding entity can further carry the categorization abilityinformation supported thereby in the categorization result messagereturned in step S45 or step S48, so that the content categorizationrequest entity stores the categorization ability information.

Similarly, this embodiment possesses the technical effect that possessedby Embodiment 3. Furthermore, by comparing with Embodiment 3, thisembodiment has the following effect: Negotiation is performed bytransmitting the content categorization initial request message to carrythe format information of the content to be categorized, while thecontent information is not directly transmitted. In this way, even ifthe content categorization providing entity does not support the formatof the content information, the content information will not beerroneously transmitted to waste the previous interaction, therebyfurther providing fast negotiation of the content categorization abilityand high efficiency of content categorization.

During the process of practical application, the content categorizationproviding entity or the content categorization request entity can obtainthe categorization ability of the other party in the mode ofsubscription. Moreover, because the categorization ability supported bythe content categorization providing entity or the contentcategorization request entity might change, while this is not known tothe other party, the content categorization providing entity or thecontent categorization request entity can further subscribe thecategorization ability changing circumstances of the other party, sothat the embodiment of the present invention provides a technicalsolution in which subscription of the categorization ability issupported and notification is performed when the categorization abilityhas changed.

Correspondingly, it is possible to realize the technical solution ofnotifying that the categorization ability has changed according to amechanism for subscription. That is, on the one hand the other partyregisters a notification interface of its own, and this step can becompleted in the process of beforehand development or by manualconfiguration, and logically expressed as the registered interface, therealization thereof is explained later. When the content categorizationability has changed, the changed party timely notifies the registeredparty via the registered interface. This mechanism for subscriptionnotification can be applied in the various embodiments mentioned above,and what is explained in detail here is merely the mechanism process ofnotifying the change of the categorization ability, specifically in thefollowing embodiment:

The content categorization request entity wants the contentcategorization providing entity to timely obtain the notification whenthe categorization ability has changed. The specific process is as shownin FIG. 5, which is a flowchart illustrating a method for contentcategorization provided by Embodiment 5 of the present invention, andspecifically includes the following steps:

Step 501: The content categorization request entity registers anotification message interface to the content categorization providingentity.

It is usual under such a circumstance for the following several modes tocomplete registration of the notification message interface.

1. The content categorization request entity directly transmits theregistration message to the content categorization providing entity.

2. The content categorization providing entity internally configures thenotification interface of the content categorization request entity,i.e. the content categorization providing entity can read its ownconfiguration file Config.ini, wherein one line of configuration of thenotification message interface is provided as:

Config.ini ... Notify = http://www.cbcs.com/notify ...

3. The content categorization providing entity is fixed with anotification interface during development, and the contentcategorization request entity configures according to the fixedstandard, i.e. the content categorization providing entity transmits abroadcasting message to an address prescribed by itself when thefunction has changed, for instance, by transmitting a notificationmessage to 192.168.1.254:9999, and if the content categorization requestentity wishes to learn of the ability change of the contentcategorization providing entity, it can listen the broadcasting messageat the port of 192.168.1.254:9999.

4. Both of the entities configure certain notification interfaces inconformity with a promulgated standard.

Step 502: The content categorization providing entity returns aregistration success message. This is an optional step in the process ofpractical application.

Step 503: When the content categorization ability of the contentcategorization providing entity has changed, the content categorizationproviding entity prepares to notify the content categorization abilitychange notification message.

Step 504: The content categorization providing entity notifies thechange of the categorization ability according to the interfaceregistered by the content categorization request entity.

An example is taken below, in which the content categorization requestentity provides a section of a new motion picture A.mpg for a provider Aand wishes that the motion picture can be categorized through a CBCSserver, to explain in greater detail the process of the method describedin the foregoing embodiment of the present invention.

Moreover, to make the explanation clearer and easier for comprehension,it is supposed in this embodiment that:

1. the provider A supports the Chinese movie categorization standard,namely CN-Classification; and

2. the CBCS server only supports motion pictures in the form of MPG, andsupports motion picture information description of MPEG-21.

Referring to FIG. 6, which is a flowchart illustrating another methodfor content categorization provided by Embodiment 5 of the presentinvention, the following steps are specifically included:

Step 601: The content providing system of the provider A transmits acontent categorization ability request to the CBCS server.

The categorization ability supported by the CBCS server is requested bytransmitting a content categorization request, for instance, by thefollowing OPTION command:

<CBCSCommand> <OPTION CmdID = “1”/> </CBCSCommand>

Step 602: The CBCS server returns the categorization abilities supportedthereby.

For instance, the categorization abilities supported thereby returned inthis embodiment are as follows: The supported content types are MEG,MPEG-21 and JPEG/GIF, the supported content code is gzip, the supportedlanguages are Danish and English, the acceptable maximum content lengthis 4096 BYTE, the supported content locators are URI and SMS shortcodes, the supported content identifiers are ISBN and ISAN, thesupported digital abstract algorithms of the content abstract are MD5,SHA-1 and RIPEMD-160, the supported reduction formats of the contentabstract are AutoTXT and Movie, the supported categorization rules areCN-Classification, ESRB, MPAA and ICRA, the supported signaturealgorithms are RSA (which supports the corresponding digital abstractalgorithms of MD-5, SHA-1 and RIPEMD-160), DSA (which supports thecorresponding digital abstract algorithm of MD-5) and ECDSA (whichsupports the corresponding digital abstract algorithm of MD-5). Thereturned information formats are as follows:

<CBCSCommand> <ContentType RefCmd= “1”> <MPG/> <MPEG-21/> <JPEG/GIF></ContentType> <ContentEncoding> <gzip> </ContentEncoding><ContentLanguage> <da> <en> </ContentLanguage> <ContentLength> <4096></ContentLength> <ContentLocator> <URI> <SMS> </ContentLocator><ContentIdentifier> <ISBN> <ISAN> </ContentIdentifier><ContentDigest_DigitalDigest> <MD5> <SHA-1> <RIPEMD-160></ContentDigest_DigitalDigest> <ContentDigest_ReduceForm> <AutoTXT><Movie> </ContentDigest_ReduceForm> <CategorizationScheme><CN-Classification> <MPAA> <ESRB> <ICRA> </CategorizationScheme><Signature> <RSA> <MD-5> <SHA-1> <RIPEMD-160> </RSA> <DSA> <MD-5> </DSA><ECDSA> <MD-5> </ECDSA> </Signature> </CBCSCommand>

Step 603: The content providing system of the provider A revises thecontent format of A.mpg according to the returned support format, usesMPEG-21 to describe the content and packs the content via ZIP.

Specifically, in accordance with the obtained content categorizationability of the CBCS server, the content providing system of the providerA determines the content type that is provided for the CBCS server tocategorize contents according to ContentType, determines the codingformat that is provided for the CBCS server to compress the contents tobe categorized according to ContentEncoding, determines the contentdescription language that is provided for the CBCS server to categorizecontents, determines the content maximum length that is provided for theCBCS server to categorize contents according to ContentLength,determines the content locator type that is provided for the CBCS serverto categorize contents according to Contentlocator, determines thecontent identifier type that is provided for the CBCS server tocategorize contents according to ContentIdentifier, determines thedigital digest corresponding algorithm of the content digest that isprovided for the CBCS server to categorize contents according toContentDigest_DigitalDigest, determines the corresponding type of thereduction form of the content digest that is provided for the CBCSserver to categorize contents according to ContentDigest_ReduceForm,determines the categorization rule requested thereby and supported bythe CBCS server according to CategorizationScheme, and determines thesignature algorithm of the confidence verification supported by the CBCSserver according to Signature. When the content categorization requestentity is an entity (such as a content screening entity) that should beverified, this parameter is especially valid, and the entity candetermine the configuration of the signature algorithm supported therebyaccording to this value.

Step 604: The content providing system of the provider A transmits acategorization request to the CBCS server, with the re-formatted A.mpgattached therewith. The corresponding command formats are as follows:

<CBCSCommand> <Categorization CmdID = “2”/> <Content> <......></Content> </CBCSCommand>

Step 605: The CBCS server requests the supported categorization ability,such as the categorization format, from the content providing system ofthe provider A, by the following OPTION commands:

CBCSCommand> <OPTION CmdID = “4”/> </CBCSCommand>

Step 606: The content providing system of the provider A returns thecategorization ability, such as the categorization format, supportedthereby to the CBCS, by the following commands:

<CBCSCommand> <ContentType RefCmd=“4”> <CN-Classification/></ContentType> </CBCSCommand>

Step 607: The CBCS server categorizes the A.mpg according to thesupported categorization ability (categorization standardCN-Classification) returned by the content providing system of theprovider A.

Step 608: The CBCS server returns the categorization results of theforegoing steps, by the following commands:

<CBCSCommand> <CategorizationRes RefCmd=“2”> <Level 3></CategorizationRes> </CBCSCommand>

Moreover, it is possible to apply the aforementioned mechanism forcontent categorization ability change notification to this embodiment,i.e. in the case the provider A wants to be timely notified when thecategorization ability supported by the CBCS server has changed. Forinstance, the CBCS server in this embodiment originally supportsMPEG-21, but with the subsequence change in the system the ability forsupport becomes MPEG-7, so that it is necessary to timely notify theprovider A.

The specific process is as shown in FIG. 7, which is a flowchartillustrating still another method for content categorization provided byEmbodiment 5 of the present invention, and includes the following steps:

Step 701: The content providing system of the provider A transmits aregistration request to the CBCS server to register its notificationmessage interface. The specific command format can be as follows:

<CBCSCommand> <NotificationReg CmdID = “1” Address =http://www.sp1.com/cbcs/notification /> </CBCSCommand>

Step 702: The CBCS server returns a acknowledgement message to thecontent providing system of the provider A, with the following specificformat:

<CBCSCommand> <NotificationRsp> OK </NotificationRsp> </CBCSCommand>

Step 703: The categorization ability supported by the CBCS server haschanged, and the CBCS determines the categorization ability changecontent to form a change notification message.

Step 704: The CBCS server notifies the content providing system of theprovider A of the result of its categorization ability change via theaforementioned interface, with the specific message format as follows:

TO: http://www.sp1.com/cbcs/notification / <CBCSCommand> <Notification/><ContentType RefCmd= “1”> <MPEG-7/> </ContentType> </CBCSCommand>

As can be known from the description of the above embodiments and modesof execution, the embodiments of the present invention can fully learnof the content categorization ability through the categorization abilitynegotiation or the subsequent updating operations of the categorizationability. Therefore, the content categorization request entity or thecontent categorization providing entity can obtain the mutual contentcategorization ability information in a detailed, clear, accurate andtimely manner. In this way, it is easy for the subsequent contentcategorization request entity to pertinently request the contentcategorization, and for the content categorization providing entity topertinently perform the content categorization and provide the contentcategorization result. Thus, the possibility of failure for contentcategorization is reduced due to lack of support of the mutualcategorization abilities between the content categorization entities,and the efficiency of content categorization is increased. On the otherhand, serving as the content categorization request entity, when thecontent screening entity needs to be confidence-verified, it is possibleto obtain the digital signature algorithm provided by the contentcategorization providing entity for performing confidence verificationof the pre-categorized information through the categorization abilitynegotiation. In this way, it is possible to help the content screeningentity configure the corresponding algorithm in advance, thus ensuringcheck on the pre-categorized content.

As can be clearly known to those skilled in the art through thedescription of the foregoing embodiments, the present invention can berealized by hardware, or realized by the necessary hardware platformwith the aid of software. On the basis of such understanding, thetechnical solution of the present invention can be embodied in the formof a software product, which can be stored in a nonvolatile storagemedium (such as a CD-ROM, a U disk, a mobile hard disk, and the like),and includes plural instructions enabling a computer device (such as apersonal computer, a server, or a network device) to execute the methodrecited in each embodiment of the present invention.

Apparently, it is possible for those skilled in the art to makevariations and modifications to the embodiments of the present inventionwithout departing from the spirit and scope of the present invention.Accordingly, if these variations and modifications to the embodiments ofthe present invention fall within the purview of the claims of thepresent invention or equivalent thereof, it is intended for the presentinvention to also cover these variations and modifications.

What is claimed is:
 1. A method for content categorization, comprising:transmitting, by a content categorization request entity, acategorization ability negotiation request to a content categorizationproviding entity to request categorization ability of the contentcategorization providing entity; receiving, by the contentcategorization request entity, the categorization ability of the contentcategorization providing entity from the content categorizationproviding entity; receiving, by the content categorization requestentity, the categorization ability negotiation request from the contentcategorization providing entity; returning, by the contentcategorization request entity, the categorization ability supported bythe content categorization request entity to the content categorizationproviding entity; requesting, by the content categorization requestentity, content categorization from the content categorization providingentity according to the categorization ability; and receiving, by thecontent categorization request entity, a categorization result of thecontent from the content categorization providing entity.
 2. The methodfor content categorization according to claim 1, further comprising:requesting, by the content categorization request entity, association ofcontent with a category from the content categorization providing entityaccording to the categorization ability.
 3. The method for contentcategorization according to claim 2, wherein the requesting stepcomprises: correspondingly processing the content to be categorizedaccording to the categorization ability, to request association ofcontent with category from the content categorization providing entitywith the processed content.
 4. The method for content categorizationaccording to claim 2, wherein before the transmitting step, the methodfurther comprises: determining, by the content categorization requestentity, whether valid categorization ability of the contentcategorization providing entity has been stored; if the validcategorization ability of the content categorization providing entityhas been stored, requesting, by the content categorization requestentity, association of content with category from the contentcategorization providing entity according to the stored categorizationability of the content categorization providing entity; and if the validcategorization ability of the content categorization providing entityhas not been stored, transmitting, by the content categorization requestentity, the categorization ability negotiation request to the contentcategorization providing entity, for requesting association of contentwith category from the content categorization providing entity accordingto the categorization ability.
 5. The method for content categorizationaccording to claim 1, wherein the categorization ability negotiationrequest is carried in one of the group of message types consisting of: acontent categorization ability negotiation request message, a contentcategorization request message, an authentication message, and anassociation of content with category request message.
 6. The method forcontent categorization according to claim 1, wherein the step of thereceiving categorization result comprises: receiving, by the contentcategorization request entity, the categorization result of categorizingthe content by the content categorization providing entity according tothe categorization ability supported by the content categorizationrequest entity.
 7. The method for content categorization according toclaim 1, wherein the categorization ability of the contentcategorization providing entity includes one of the group consisting of:a content locator supported by the content categorization providingentity; a content identifier supported by the content categorizationproviding entity; and a content abstract type supported by the contentcategorization providing entity.
 8. The method for contentcategorization according to claim 1, wherein after the step of receivingthe categorization ability of the content categorization providingentity from the content categorization providing entity, the methodfurther comprises: configuring at least one of the group consisting ofcategorization ability and confidence verification ability supported bythe content categorization request entity according to thecategorization ability.
 9. A method for content categorization,comprising: receiving, by a content categorization providing entity, acategorization ability negotiation request from a content categorizationrequest entity; returning, by the content categorization providingentity, categorization ability of a content categorization providingentity to the content categorization request entity; sending, by thecontent categorization providing entity, the categorization abilitynegotiation request to the content categorization request entity; andreceiving, by the content categorization providing entity, thecategorization ability supported by the content categorization requestentity from the content categorization request entity; receiving, by thecontent categorization providing entity, a content categorizationrequest from the content categorization request entity according to thecategorization ability; categorizing, by the content categorizationproviding entity, the content according to the content categorizationrequest and the categorization ability supported by the contentcategorization request entity; and returning, by the contentcategorization providing entity, a categorization result to the contentcategorization request entity.
 10. The method for content categorizationaccording to claim 9, wherein the categorization ability negotiationrequest is carried in one of the group of message types consisting of: acontent categorization ability negotiation request message, a contentcategorization request message, an authentication message, and anassociation of content with category request message.
 11. The method forcontent categorization according to claim 9, further comprising:receiving, by the content categorization providing entity, anassociation of content with category request from the contentcategorization request entity according to the categorization ability;associating, by the content categorization providing entity, contentwith category according to the association request if there is acategory corresponding to the content; categorizing the content toobtain a category and associating the content with the category if nocategory to which content corresponds is present; and returning, by thecontent categorization providing entity, an association result to thecontent categorization request entity.
 12. A content categorizationrequest entity, comprising a processor, and a non-transient computerreadable medium, wherein the computer readable medium, furthercomprising: a categorization ability requesting unit, configured torequest categorization ability from a content categorization providingentity; a categorization ability receiving unit, configured to receivethe categorization ability of the content categorization providingentity from the content categorization providing entity; a transmittingunit, configured to request content categorization from the contentcategorization providing entity according to the category ability of thecontent category providing entity; and a receiving unit, configured toreceive a categorization result of the content from the contentcategorization providing entity; wherein the content categorizationrequest entity further configures to receive the categorization abilitynegotiation request from the content categorization providing entity;and return the categorization ability supported by the contentcategorization request entity to the content categorization providingentity.
 13. The content categorization request entity according to claim12, wherein the transmitting unit is further configured to requestassociation of content with category from the content categorizationproviding entity according to the categorization ability.
 14. Thecontent categorization request entity according to claim 12, furthercomprising: a content processing unit, configured to correspondinglyprocess content information to be categorized according to thecategorization ability, and request content categorization from thecontent categorization providing entity via the transmitting unit withthe processed content information.
 15. The content categorizationrequest entity according to claim 12, wherein the categorization abilitynegotiation request is carried in one of the following messages: acontent categorization ability negotiation request message, a contentcategorization request message, an authentication message, and anassociation of content with category request message.
 16. A system forcontent categorization, comprising: a content categorization requestentity having a processor and a non-transient computer readable medium,configured to: transmit a categorization ability negotiation request toa content categorization providing entity to request categorizationability of the content categorization providing entity, receive thecategorization ability of the content categorization providing entityfrom the content categorization providing entity, receive thecategorization ability negotiation request from the contentcategorization providing entity, return the categorization abilitysupported by the content categorization request entity to the contentcategorization providing entity; request content categorization from thecontent categorization providing entity according to the categorizationability and receive a categorization result of the content from thecontent categorization providing entity; and wherein the contentcategorization providing entity having the processor and thenon-transient computer readable medium, is configured to: receive thecategorization ability negotiation request from the contentcategorization request entity, return the categorization ability of thecontent categorization providing entity to the content categorizationrequest entity, receive a content categorization request from thecontent categorization request entity according to the categorizationability, categorize the content according to the content categorizationrequest and the categorization ability supported by the contentcategorization request entity, and return a categorization result to thecontent categorization request entity.
 17. The system for contentcategorization according to claim 16, wherein the content categorizationrequest entity is further configured to request association of contentwith category from the content categorization providing entity accordingto the categorization ability, and wherein the content categorizationproviding entity is further configured to receive a request forassociation of content with category from the content categorizationrequest entity, to associate the content with the category.
 18. Thesystem for content categorization according to claim 16, wherein thecategorization ability negotiation request is carried in one of thegroup of message types consisting of: a content categorization abilitynegotiation request message, a content categorization request message,an authentication message, and an association of content with categoryrequest message.
 19. The system for content categorization according toclaim 16, wherein the categorization ability of the contentcategorization providing entity includes one of the group consisting of:a content locator supported by the content categorization providingentity; a content identifier supported by the content categorizationproviding entity; and a content abstract type supported by the contentcategorization providing entity.